Step 2:Shuck the oysters, discarding the top shell. Take pains not to spill the juices. Arrange the oysters on a shellfish rack (or rimmed baking sheet if you don’t have one). Spoon 2 teaspoons barbecue sauce over each oyster and add a splash of hot sauce and mezcal. Sprinkle the cheese on top.

Step 3: Place the shellfish rack on the grill grate. (Alternatively, carefully balance the oyster shells between the bars of the grill grate.) Grill the oysters until the juices bubble and the cheese melts, 3 to 5 minutes. Transfer the oysters to a platter or plates. Top with sprigs of cilantro and serve lime wedges for squeezing.